Key-board for piano-fortes



(Nd Model.)

W. H. IVERSl KEY BOARD FOR PIANO PORTES.

No. 363,240.` Patented May 17,1887.V

Wfzewes. .y jizz/wahr.

f2? Wff/m UNITED STATES PATENT OEEICE.

WILLIAM HY. IVERS, OF DEDHAM, ASSIGNOR TO THE IVERS St POND PIANO i COMPANY, OF BOSTON, MASSACHUSETTS.

KEY-BOARD FOR PIANO-FORTES.

SPECIFICATION forming part of Letters Patent No. 363,240, dated May 17, 1887.

l Application filed March 23,1887. Serial No. 232,127. (N o model.)

T all whom, it may con/cern:

Be it known that I, WILLIAM H. IvERs, a citizen'of the United States, residing at Dedham, in the county of Norfolk and State of Massachusetts, have invented certain new and useful Improvements in Key-Boards for Piano- Fortes; and I do hereby declare the following tobe a full, clear, and exact description-of the invention, .such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to lettersor figures of reference marked thereon, which form a part of this specification.

This invention relates tol piano-fortes; and it consists in the peculiar construction of the key-board, so called, by which atmospheric changes, particularly humidity, are prevented Y from influencing the action of the instru- 2o ment. In other words, the object of my invention is to maintain the risers upon the inner end of the keys always in the same relative position with respect to the action, so

termed, of the instrument.

The drawings represent, in Figure 1, an isometric view of a keyboard embodying my invention. Fig. 2 is a vertical cross-section ofa key-board with the key-frame and key mounted thereon. Fig. 3 represents a modifled construction of the key-board.

In the accompanying drawings, and upon reference to Fig. 2, I have represented a vertical transverse section of a key-board and key-frame of a pianoforte arranged as now ,35 most generally constructed. First and lowermost, and rmly affixed horizontally in. the piano-forte case,is the key-board A. lUpon and above this rests the key-frame B, while surmounted upon thelatter are pivotally secured 4o in proper bearings the keys G, only one of which is here shown. In this general construction the key-board has usually been com posed of wood, to render the instrument as light as possible compatible with strength. Upon the key-board, as shown in the drawings, rests and is secured by screws or other suitable fastenings the key-frame B, which carries the keys.

In consequence of the varying humidity or 5o dryness of the atmosphere, the wood composy one with the other.

ing the key-board is liable to swell or contract, which act displaces the key-frame and keys, with their risers, from the properrelative positions for whichthe latter are regulated, and which they should bear to the action of the instrument. Herein arises the difficulty which I have endeavored to overcome in my present improvements. As a result of this slight variation in the position of the key-board a similar but corresponding change is effected in 6o the key-frame B, which alters the position of the keys, also the risers mounted on the latter,

and changes the relative position of said risers with respect to the action of the instrument, which, as heretofore constructed, is materially affected by all or any changes in the humidity or dryness of theatmosphere, and4 the pianoforte must be readj usted. Upon reference to the drawings, A repre'- sents the keyboard, made up of several pieces 7c of well-seasoned wood firmly glued and united together. `This extends longitudinally between and is affixed to the ends ofthe case of the instrument. (Not shown.) Above this is placed the key-frame B, which is likewise made ofwood 7 5 and constructed with three rails, a l1 c, united by interconnecting panels dd. In the center rail, b, is firmly set a seriesof metallic pins, e, which extend longitudinally of and are parallel with the front of the instrument at D, said pins 8o being suitably spaced to accommodate and permit the mounting of the keys, one of which, C, is represented pivotally secured thereon. A ring of felt, f, is disposed about said pins to interpose between the key and the key-frame, and 8 5 thereby cushion the key. Similarly upon the front rail, a, of the key-frame B is arranged asecond series of pins, f which serve as guides to maintain each and every key in parallelism,

Furthermore, it will be 9o observed that the top of the front rail, a, in the key-frame is slightly below the level of the upper surface of the center rail, b; hence, as each key is nicely balanced upon its central pivot-pin, e, a short drop is permitted to the front or linger portion, t', of the key C whenever pressure is brought upon thelatter. This consequently raises the rear end of said key, which is furnished with a riser, E. The latter acts with the jack' j, so called, (only the roo lower portion-of which is shown,) to operate the hammer and damper eo-operating therewith. Presuming the above description clearly specifies the relation of said parts mentioned in an ordinarily-constructed piano-forte, it will readily be perceived that the keys are supported on the key-frame, which latter is affixed to the key-board; but byl this arrangement, should any expansion of said key-board, however small, occur, it will, as I have before stated, naturally affect the action of the instrument, since that part of the key to which are affixed the risers is raised or lowered. Thus the position of said risers with respect to the action of the instrumentis altered, and said action is rendered too hard, or the re` verse, dependent upon the position or locality of the piano-forte and the condition of the atmosphere surrounding it. To obviate this difficulty in the shrinking or swelling of the wood composing the key-board at a point beneath the risers, and taking advantage of one of the natural properties inherent in all woody iibers-which 'is that it does not contract or expand longitudinally of the fibers composing itI have inserted within the key-board, at the rear and directly beneath the point of support of said key-frame at this particular part, as shown in Fig. 2, a continuous piece of wood, y, in which the fibers or grain shall be vertically disposed, and is to project above the level of the rear rail of said key-board, while it is iiush with the front rail thereof. In lieu of this single continuous strip, a series of pins maybe disposed as represented in Fig. 3, the iibers of which they are composed being also vertically disposed.

Thus the obj eet of my invention, it will readily be understood, is to maintain the positions of the risers always permanent with respect to the action of the instrument after the latter has been properly regulated. The key-frame is new secured to the key-board by screws h h', the latter being entered into the strip or series of pins g. Thus a fixed support is obtained for the key-frame just beneath the risers, and so long as these remain undisturbed the action continues in its normal condition of adjustment with respect to the risers and keys. Itis, moreover, evident that the slight alteration in the front portion of the key-frame, or of the keys, due to the swelling or contraction of the key-board, is immaterial, provided the riser end of the keys remains stationary. This, I believe, is effeetually accomplished by the construction hereinbefore described.

In the above explanation I have premised that the continuous strip g is made of wood; but I do not desire to be limited to the particular material from which said strip or pins are to be made. I consider the gist of my iuvention to be embodied in the employment with a key-board of wood of a continuous strip or series of posts which shall extend cntirely through the key-board. Moreover, the material of which said strips or series of posts are composed is to have a coefficient of expansion or contraction less than that of the wood composing the frame. Hence the heat or cold, humidity or dryness, to which the wood of the key-board may be subjected will not affect materially the material upon which the keyframe rests, and the latter will remain undisturbed. It is evident that only the upper and under exposed portions of the keyboard are subject to the varying surrounding atmospheric conditions; but since the strip or posts g are located transversely of such movement the relative displacement or change in they bers of the wood composing the key-board, as they contract or expand laterally, does not alter the position of said strips or posts, as hereinbefore explained.

I am aware that metallic key-boards have been employed; but these are heavy and costly and objectionable, owing to the difficulty in leveling them prior to insertion of the action.

What I desire to claim isl. As a new article of manufacture, a keyboard provided at its rear portion, beneath the risers, with astrip or series of posts which extend entirely through said key-board, the material composing said strip or posts having a coefficient of expansion or contraction less than that of the material forming the keyboard, substantially as and for the purposes specified.

2. As a new article of manufacture, a keyboard composed of wood and provided upon its rear portion with a continuous strip or series of strips or pins of similar material having the grain of the wood vertically disposed, substantially for the purposes herein set forth.

3. In combination with a series oi' keys, C,

Ypivotally mounted upon the key-frame B, a

key-board, A, constructed with astrip orseres of pins, g, disposed as herein described, and the key-frame I3, supported by said strip or its equivalent at a point beneath the risers, substantially as herein described.

In testimony whereof I affix my signature in presence of two witnesses.

VILLIAM II. IVERS.

Witnesses:`

HANDEL POND, IVI. E. Lopen.

IOO

IIO 

